Chandler climate

Chandler Frost Dates and Growing Season

NOAA 1991-2020 normals for Chandler, 0.5 km from Chandler, elevation 958 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Chandler. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around April 7 and the first fall freeze around October 30, a growing season of about 205 days.

Median at 36°F
last April 19, first October 21
Median at 32°F
last April 7, first October 30
Median at 28°F
last March 28, first November 7

Last freeze in spring

The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.

Threshold10%20%30%40%50%60%70%80%90%
36°FMay 4Apr 30Apr 26Apr 23Apr 19Apr 16Apr 14Apr 10Apr 5
32°FApr 23Apr 18Apr 14Apr 10Apr 7Apr 4Apr 1Mar 29Mar 23
28°FApr 12Apr 6Apr 3Mar 31Mar 28Mar 25Mar 20Mar 15Mar 8
24°FApr 1Mar 28Mar 24Mar 19Mar 15Mar 11Mar 6Mar 3Feb 26
20°FMar 23Mar 17Mar 12Mar 8Mar 4Mar 1Feb 25Feb 20Feb 12
16°FMar 15Mar 9Mar 4Feb 28Feb 24Feb 19Feb 13Feb 6Jan 30

First freeze in fall

The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.

Threshold10%20%30%40%50%60%70%80%90%
36°FOct 8Oct 12Oct 15Oct 19Oct 21Oct 25Oct 27Oct 31Nov 5
32°FOct 15Oct 20Oct 24Oct 27Oct 30Nov 1Nov 4Nov 9Nov 15
28°FOct 24Oct 29Nov 1Nov 4Nov 7Nov 11Nov 14Nov 19Nov 26
24°FOct 31Nov 5Nov 9Nov 14Nov 17Nov 21Nov 26Nov 30Dec 5
20°FNov 9Nov 15Nov 21Nov 26Nov 29Dec 2Dec 5Dec 11Dec 18
16°FNov 20Nov 27Dec 1Dec 5Dec 9Dec 15Dec 20Dec 26Jan 4

Growing season length

Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.

Threshold10%20%30%40%50%60%70%80%90%
36°F206198192188184181176170164
32°F227219214209205200194189182
28°F250242236231227222217211203
24°F274264258253247243237230220
20°F296287280274268263258251243
16°F323312303297290285278271261

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
100% of years
20°F or colder
100% of years
16°F or colder
100% of years

Degree days

A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.

Heating degree days, base 65°F
3,514
Cooling degree days, base 65°F
2,001
Growing degree days, base 40°F
8,011
Growing degree days, base 45°F
6,512
Growing degree days, base 50°F
5,164
Growing degree days, base 55°F
3,963
Growing degree days, base 60°F
2,908

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January820018
February636144
March43410149
April19547322
May45160580
June1394843
July05361,001
August0508973
September18272705
October15865384
November4497122
December756024

What this means

NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.

The station is 0.5 km from Chandler. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00341684 (Chandler). Public domain.